Anemia is a condition in which the blood is either low in total volume or is deficient in red blood cells or hemoglobin. Anemia can occur for several reasons including hemorrhage and following chemotherapy. Erythropoietin stimulating agents are commonly administered to stimulate red blood cell production and thus, treat anemia. However, these agents often are ineffective at treating anemia because they are slow to act, are ineffective in iron deficient subjects, and can cause high blood pressure thereby increasing risk of death, heart failure, heart attack and stroke. Therefore, a need exists for methods of modulating erythropoiesis in anemic subjects, which are quicker to act, and not associated with the aforementioned side effects. Furthermore, there are cases when there are too many red blood cells made (polycythemia vera); a potentially fatal condition that has no specific treatment. A drug that could reduce the production of red cells in the bone marrow is needed.